Adding Triggers for a Lambda@Edge Function

A Lambda@Edge trigger is one combination of CloudFront distribution, cache behavior,
and event that causes a function to
execute. You can specify one or more CloudFront triggers that cause the function
to run. For example, you can create a
trigger that causes the function to execute when CloudFront receives a request
from a viewer for a specific cache behavior
you set up for your distribution.

Tip

If you're not familiar with CloudFront cache behaviors, here's a brief overview. When
you create a CloudFront distribution,
you specify settings that tell CloudFront how to respond when it receives different
requests. The default settings are
called the default cache behavior for the distribution. You can set up additional
cache behaviors that define how
CloudFront responds under specific circumstances, for example, when it receives
a request for a specific file type. For
more information, see Cache Behavior
Settings.

At the time that you create a Lambda function, you can specify only one trigger. But
you can add more triggers to the
same function later in one of two ways: by using the Lambda console or by editing
the distribution in the CloudFront
console.

Using the Lambda console works well if you want to add more triggers to a function
for the same CloudFront
distribution.

Using the CloudFront console can be better if you want to add triggers for multiple
distributions because it's
easier to find the distribution that you want to update. You can also update
other CloudFront settings at the same
time.